Craig was director of the Mayflower Centre in Canning Town between 1995 and 2004.
Craig first stood for Newham Council in 1998 as a Christian Democrat candidate in Ordnance ward and in 2001 he stood in a by-election for Beckton ward.
He was elected to Newham Council for Canning Town South in the 2002 local elections becoming the only opposition councillor. In the 2006 elections he was re-elected with an increased majority as part of a group of three Christian Peoples Alliance councillors. However he lost his council seat in 2010.
He stood in the elections for directly elected mayor of Newham in 2002, 2006 and 2010, coming fourth each time.
He became leader of the Christian Peoples Alliance in 2004 and led the party in the 2005 general election and the 2010 general election.
In 2008 London mayoral election Craig stood as a "Christian Choice" candidate, representing the Christian Peoples Alliance and the Christian Party. He received 39,249 first choice votes (1.62%) and 80,140 second choice votes (4.00%), finishing sixth in the first round of voting, and being eliminated for the second.
Craig opposed the building of the London Markaz Mosque; he said that while he supports the right to worship, he had fears over the impact upon the community and on security. He also opposed the opening of one of the regional casinos in Newham, campaigned to end the DESO-funded arms fair and played a leading role in the campaign to save the Queens Road Market.
In 2011 he was criticised for referring to the "Gaystapo" of "gay-rights storm troopers" with "Nazi expansionist ambitions". In 2013 Craig became the spokesperson for a new group called 'Gay Marriage No Thanks'. In July 2009, Craig described the Bishop of Rochester, the Rt Revd Dr Michael Nazir-Ali, as 'saintly' and 'honourable' for stating that homosexuals should "repent and be changed". In 2013, he compared gay rights activists in the UK to Pakistani fundamentalists, claiming that 'away from the spotlight gay activists in the UK are as up for criminal violence as any turbaned Muslim militant'.
Craig has served on the Council of the Movement for Christian Democracy, the Canning Town Partnership Board and the Council for Racial Equality in Newham.
In October 2014, Craig joined UKIP. In the 2015 general election, he was the UKIP candidate for Brent North but lost his deposit.
His selection as UKIP candidate for South West constituency in the London Assembly election, 2016 prompted the resignation of the runner-up, LGBT activist and former parliamentary candidate, Richard Hendron, who described Craig as "a nasty, homophobic individual who is driven by hatred of the LGBT community". UKIP's deputy chairwoman, Suzanne Evans called for the removal of Craig for his "offensive" homophobic remarks; she went on to say he should be expelled from the party following Craig's comparison to gays being like "Nazis". He came fifth in the election for the South West constituency, gaining 7% of the vote.
In the 2017 general election, he is the UKIP candidate for Witney.